1. Field of the Invention
This invention relates to a composition, and a method for preparing the composition, for use in packed beds designed to scavenge and remove sulfur compounds found in hydrocarbon fluids, with the composition made from the combination of carrier particles, oxide particles, and non-aqueous liquid moistening agents. More specifically, the present invention relates to the use of non-aqueous liquid moistening agents in moistening oxide-bearing carrier particles.
2. Description of the Related Art
The use of water moistened carriers with iron oxide particles were disclosed in U.S. Pat. No. 5,320,992, which issued on Jun. 14, 1994. Oxide particles are used in reactor beds to remove sulfur compounds and sweeten hydrocarbon fluids, such as gasoline. Typically the oxide particles are mixed with a carrier composition, so that the composition used to sweeten the gas is a combination of carrier and oxide particles.
In order to have a process wherein oxide particles efficiently remove sulfur compounds from gasoline, it is necessary for the oxide particles to remain spaced apart from one another. A moistening agent is used to hold the oxide particles onto the carrier particles, so that the oxide particles will remain spaced apart. If a moistening agent is not used the oxide particles will flow through the reactor bed with the gasoline and clump together, which is undesirable because clumping decreases the uniform permeability and porosity of the reactor bed. Additionally, the clumping of the oxide particles will result in decreased contact between the oxide particles and the hydrocarbon fluids, resulting in a lesser amount of sulfur being reacted and an increased likelihood that the hydrocarbon fluids will remain contaminated. It has been known to moisten the oxide-bearing carrier particles with water so as to allow the oxide particles to adhere to the carrier particles found in a reactor bed. However, the use of water alone as a moistening agent suffers from a number of disadvantages.
One disadvantage associated with water, is that it will migrate into the hydrocarbon fluids, including gasoline, being treated in the present process, known as the packed bed process. This is disadvantageous because commercial providers of, for instance, gasoline can sell fluids with only a very limited amount of water present in the gasoline. In fact, if too much water migrates into the gasoline, then the gasoline must be treated to remove the water that migrated into the gasoline. Another disadvantage associated with the use of water is that the water used to moisten the carrier particles can contaminate the hydrocarbon fluid being, sweetened. Essentially water is considered a contaminant that must be removed before the gasoline can be sold. The migration of water into the gasoline is especially undesirable because the gasoline must be passed through an additional processing step to remove the water, which can be costly and potentially raises the price of the gasoline. As can be seen, the use of water as a moistening agent is undesirable because it readily migrates into hydrocarbon fluids being treated in a packed bed process and because once the water migrates into the hydrocarbon fluids it is considered a contaminant that must be removed.
Thus, it is desirable to have a moistening agent available for moistening oxide-bearing carrier particles that is not considered a contaminant of hydrocarbon fluids and that does not readily migrate into the hydrocarbon fluids being treated. Specifically, it is desirable that water alone is not used as a moistening agent in the packed bed process.